Hsueh-Ling Chang, Yuan-Ting Hsu and Lu-Chuan Li contributed equally to this work.
Polyamine effects on protein disulfide isomerase expression and implications for hypersalinity stress in the marine alga Ulva lactuca Linnaeus1
Article first published online: 5 NOV 2013
© 2013 Phycological Society of America
Journal of Phycology
Volume 49, Issue 6, pages 1181–1191, December 2013
How to Cite
Li, L.-C., Hsu, Y.-T., Chang, H.-L., Wu, T.-M., Sung, M.-S., Cho, C.-L., Lee, T.-M. (2013), Polyamine effects on protein disulfide isomerase expression and implications for hypersalinity stress in the marine alga Ulva lactuca Linnaeus1. Journal of Phycology, 49: 1181–1191. doi: 10.1111/jpy.12129
Chung-Lung Cho and Tse-Min Lee are co-corresponding authors.
- Issue published online: 9 DEC 2013
- Article first published online: 5 NOV 2013
- Accepted manuscript online: 1 OCT 2013 12:25PM EST
- Manuscript Accepted: 19 AUG 2013
- Manuscript Received: 29 JUN 2013
- National Science Council. Grant Numbers: 96-2311-B-110-002-MY3, 99-2311-B-110-001-MY3, 98-3114-B-110-001-, 99-3113-P-110-001-, 100-3113-P-110-001-
- hypersalinity stress;
- protein disulfide isomerase;
- Ulva lactuca
Full-length protein disulfide isomerase (UfPDI) cDNA was cloned from the intertidal macroalga Ulva lactuca Linnaeus. Modulation of UfPDI expression by stresses and polyamines (PA) was studied. UfPDI transcription and enzyme activity were increased by hypersalinity (90) or high light illumination (1,200 μmol photons · m−2 · s−1), decreased by the addition of 100 μM CuSO4. An exposure to a salinity of 90 decreased PA contents. Treating with PA biosynthetic inhibitors, D-arginine (D-Arg) or α-methyl ornithine (α-MO), led to a further decrease and also inhibited UfPDI expression and recovery of the growth rate. These results suggest that PAs are required to activate UfPDI expression with hypersalinity, even PA contents are decreased at a salinity of 90. The induction of UfPDI expression by hypersalinity of 90 and tolerance to hypersalinity could be enhanced if internal PA contents rise. Sung et al. (2011b) showed that PA contents could be increased by pretreating with putrescine (Put, 1 mM), spermidine (Spd, 1 mM), or spermine (Spm, 1 mM) at a salinity of 30. Therefore, PA pretreatment effect on UfPDI expression was examined. Pretreatment with Spd and Spm, but not with Put, enhanced UfPDI expression after transferred to a salinity of 90 and restored the growth rate. In conclusion, induction of UfPDI expression by Spd or Spm before exposure to hypersaline conditions and continuous up-regulation after hypersalinity exposure are required for the acquisition of hypersalinity tolerance in the intertidal green macroalga U. lactuca.